Ottawa Roofing Repairs says:
October 15, 2013 at 4:08 PM
Water is driven by the rain behind the wall flashing. That wall should have ice and water shield behind the siding to keep the rain water out. Also the wall flashing should be much higher to prevent similar problems. Step flashing is a must, one step flashing per sheet of shingle. Caulking is a temporary solution, it can make things worst.
Roofer911 says:
October 16, 2013 at 4:57 AM
The step flashing along the wall was in excellent condition and did not need to be touched. If step flashing was the issue the roof would leak with all medium to heavy rains. The top of the window and roof below would only leak during a wind-driven rain towards the wall so the source is most likely coming in from above the window some where.
Ottawa Roofing Contractor says:
October 16, 2013 at 6:42 AM
J-trims can hold all the rain water and with the help of rain in can get in behind the siding. If the windows are sealed properly with ice and water shield this problem can be avoided.
Roofer911 says:
October 16, 2013 at 11:03 AM
I agree 100% about what you say about J-channels being a problem and that was most definitely part of the reason for the leak here. Also, the window had hairline fractures to the inside corners due to normal expansion and contraction and was never sealed properly. The wood sheathing underneath the ridge vent was cut to the eave which presented a big problem. To stop this leak we needed to focus on everything to be repaired or the leak would most definitely return.
